Although Gut Coat does not or will not heal gastrointestinal ulcers, it may sooth your horse’s stomach and coat the stomach lining. Gut Coat has a high concentration of Calcium Carbonate which for both people and horses has been used as a natural antacid. This is the primary ingredient that lends the most immediate comfort to your horse. With daily pre exercise treatment your horse may be more relaxed and be more manageable while also having a more consistent and stronger appetite. 4L bottle.